Device for blow-texturing at least one multifilament yarn

ABSTRACT

The device has a guide unit (1) enclosing a through hole with a conical inlet section (2). A needle unit (3) encloses a through yarn passage (4) arranged coaxially with the hole in the guide unit (1). One end of the needle unit (3) extends into the conical inlet section (2) and has a conical peripheral area (5) which, with the wall of the inlet section (2), forms a slot (6) for a blowing agent. The blowing agent is fed through a drilling (17) opening into the annular space (18) surrounding the needle unit (3) are pressed together by an elastic load, e.g. springs (11, 12). This arrangement accurately fixes the axial position of the guide unit (1) in relation to the needle unit (3), while the width of the slot (6) is accurately predetermined and unchangeable.

The invention relates to a device for blow-texturing at least onemultifilament yarn, with a guide unit containing a through bore having aconical section on one inlet side, and with a needle unit containing athrough yarn passage aligned approximately coaxially with the bore ofthe guide unit, this needle unit extending with one end into theaforementioned conical section and exhibiting on this end a conicalperipheral surface forming, with the wall of the conical section, apassage slot for a blowing medium; a feed bore for the blowing mediumterminates upstream of the passage slot into the annular chambersurrounding the needle unit, and a baffle unit is mounted on the outletside of the bore of the guide unit.

For obtaining a satisfactory texturing effect in such a device, a highoverfeed is necessary. Overfeed means the ratio between the velocity ofthe yarn fed through the yarn passage and the take-off speed of thetextured yarn exiting from the bore of the guide unit and deflected onthe baffle unit. In order to provide for a high overfeed, the passageslot for the blowing medium between the needle unit and the guide unitshould, in dependence upon the titer of the yarn, have in each case apredetermined width ranging from about 0.12 to 0.4 mm. With a given yarntiter, the width of the passage slot should always exhibit constantlyits optimum value. The precision required for this purpose is, however,difficult to obtain and must be permanently maintained.

Therefore, in known devices of the type discussed hereinabove, the guideunit and/or the needle unit are arranged in an axially adjustablefashion in a housing of the device in order to be able to adjust thewidth of the passage slot by axial shifting. However, it is practicallyimpossible with these devices to set the width of the passage slotaccurately and in a reproducible way to a desired value. Furthermore,there is the danger that the adjustment will change during the course oftime.

In general, the invention has the object of fashioning theabove-indicated device in such a way that a high and uniform texturingquality is achieved and is also permanently ensured over relatively longperiods of time.

In the device according to this invention, the object has been attainedby fixing the axial position of the guide unit with respect to theneedle unit by urging the guide unit and the needle unit against eachother by a force exerted in the axial direction.

The invention thus eliminates the feature of making the guide unit andthe needle unit axially adjustable with respect to each other andinstead presses the two units against each other with a preferablyelastic load of a predetermined magnitude. The result perforce achievedthereby is a passage slot of a predetermined, constant width between theneedle unit and the guide unit. Furthermore, it is possible withoutdifficulties to retain the two bodies so that the wall of the conicalsection of the bore in the guide unit and the conical peripheral surfaceon the needle unit are exactly coaxial to each other.

For similar reasons of precision and stability, the baffle unitpreferably cannot be axially adjusted with respect to the guide unit,either, in order to be able to set the distance between the exit orificeof the bore of the guide unit and the baffle unit. Instead, the baffleunit can be mounted to a holder to be exchangeable and furthermore to bepivotable into a threading position remote from the exit orifice of thebore of the guide unit.

Embodiments of the device according to this invention will be describedbelow with reference to the drawings wherein:

FIG. 1 is a schematic longitudinal section through a blow-texturingdevice,

FIG. 2 shows a longitudinal section through the device rotated by 90°with respect to FIG. 1,

FIG. 3 is a cross section along line III-III in FIG. 1,

FIG. 4 is a cross section along line IV-IV in FIG. 1,

FIG. 5 shows, in a view corresponding to a detail of FIG. 1, a variationof the device on an

FIG. 6 shows a cross section along line VI-VI in FIG. 5,

FIG. 7 shows, in a view similar to FIG. 1 --on a somewhat reducedscale--the exit zone of another variation of the blow-texturing device,and

FIG. 8 shows a view of the variation according to FIG. 7 as seen fromthe left-hand side in FIG. 7.

The device for the jet bulking of a multifilament yarn (orsimultaneously two or more multifilament yarns) shown schematically inFIGS. 1-4 comprises a guide unit 1, consisting of a ceramic material,for example, containing a continuous bore for the passage ofmultifilament yarn and blowing medium. This bore exhibits a conicalsection 2 on one inlet side. The vertex angle of the conical shaperanges, as usual, between 30° and 120°, for example, as shown, at about60°.

The device furthermore contains a needle unit 3 with a continuouslyextending yarn channel 4 aligned approximately coaxially with the boreof the guide unit 1. The needle unit 3 extends with one end into theconical section 2 of the bore of the guide unit 1 and exhibits at thisend a conical peripheral surface 5 forming, with the wall of the conicalsection 2, a passage slot 6 for the blowing medium.

The passage slot 6 should have an exactly predetermined width dependingon the titer of the yarn to be textured which is fed through the yarnpassage 4 and ranging from about 0.12 to 0.4 mm. In order to ensure thisexactly predetermined width of the passage slot 6, the axial position ofthe guide unit 1 with respect to the needle unit 3 is fixed inaccordance with this invention by pressing the guide unit 1 and theneedle unit 3 against each other by the exertion of a force in the axialdirection. In the illustrated embodiment, the guide unit 1 and theneedle unit 3 are guided with their peripheral surfaces in a cylindricalsleeve 7 and are in contact with each other, in the preferred versiondirectly, along a circular-ring surface 8. However, it is also possible,if desired, to arrange on the circular-ring surface 8 between the twobodies 1 and 3, for example, a shim of a predetermined thickness whichshim can be exchangeable. The annular contact surface 8 could also beconical in order to center the two units 1 and 3 additionally withrespect to each other. The guide unit 1 is in contact with a flange 7.1of the sleeve 7 while the needle unit 3 is retained in a housing 9guided on the outside of the sleeve 7, for example, as describedhereinbelow, by means of a bayonet catch. A pin 10 is seated in a borein housing 9 and extends into a bore in a flange 7.2 of the sleeve 7 inorder to prevent twisting of the housing 9 with respect to the sleeve 7.Compression springs 11 and 12 (FIGS. 2, 3) are arranged in two furtherbores in the housing 9; these springs are in contact with the flange 7.2of the sleeve 7 and urge the sleeve 7 toward the right with respect tothe housing 9 in FIGS. 1 and 2. In addition, a connecting conduit 14leads from a compressed-air connection 13 in the housing 9 to theleft-hand side of the flange 7.2, acting as a piston, so that thepressure of the introduced blowing air urges the sleeve 7 likewisetoward the right with respect to housing 9. (The connecting conduit 14is not visible in FIG. 3, but its position is indicated herein by meansof a dot-dash line.) Thus, in this way, the guide unit 1 in contact withthe flange 7.1 of the sleeve 7 is pressed against the needle unit 3,held in the housing 9, by means of an elastic load.

The compressed-air connection 13 of the housing 9 is in communication,via a lateral aperture 15 in the sleeve 7, with a recess 16 in theneedle unit 3 extending in the peripheral direction. An axially parallelfeed bore 17 for the blowing air emanates from this recess 16 andterminates into the annular chamber 18 surrounding the needle unit 3upstream of the passage slot 6. A bushing 19 consisting, for example, ofhard metal or a ceramic material is arranged in the feed bore 17; thisbushing, as illustrated in FIG. 2, exhibits a rounded inlet rim.

On the outlet side of the bore of the guide unit 1, i.e. in the flowdirection of the blowing air and in the travel direction of the yarndownstream of the exit orifice of the bore of the guide unit 1, a baffleunit 20 is arranged which has, for example, the shape of a cylindricalsleeve, as illustrated. The sleeve 20 is held exchangeably on a mandrel21 which latter is seated in a body 23 pivotable about an axle 22. Theswivel axle 22 is retained in a holder 24 affixed to the sleeve 7.Furthermore, a compression spring 25 is arranged in a bore in the holder24 and urges a ball 26 into a locking recess 27 in the body 23. Thereby,the body 23 with the mandrel 21 is fixed in the illustrated operativeposition wherein the sleeve 20, serving as a baffle member, has apredetermined small distance from the exit orifice of the bore of theguide unit 1. This distance can be varied by exchanging the sleeve 20against another sleeve with a larger or smaller external diameter. Forthreading a new multifilament yarn through the yarn passage 4 and thebore of the guide unit 1, the body 23 with the mandrel 21 can beswung--after overcoming the bias of the compression spring 25--about theaxle 22 into a threading position wherein the ball 26 locks into asecond detent recess 28 in the body 23. The sleeve 20 serving as thebaffle member is then at a distance from the guide unit 1 so that asuction gun can be placed in front of its outlet orifice.

In the illustrated embodiment, the needle unit 3, as mentioned above, isheld in the housing 9 by means of a bayonet catch. The needle unit 3carries two radial projections 29 and 30 extending behind two inwardlyoriented radial projections 31 and 32, respectively, of a bayonet ring33 retained in the housing 9. The bayonet ring 33 is releasably arrangedin the housing 9 and held, for example, by means of a snap ring 34.

The yarn G leaving the outlet orifice of the bore of the guide unit 1and impinging upon the baffle unit 20 is deflected on the baffle unit 20in such a way that it moves away from the axis of the yarn channel 4 andthe bore of the guide unit 1, as shown in FIG. 2, in a direction lyingapproximately in diametrical opposition to the direction from the axisto the air feed bore 17. The yarn G then travels in the view accordingto FIG. 2 at the bottom around the baffle member 20 and is taken off inthe upward direction. In case the thus-described device is arranged in atexturing machine so that the yarn G in the view according to FIG. 2should travel at the top around the baffle unit 20 and then should betaken off in the downward direction, then the needle unit 3 can beinserted for this purpose in the sleeve 7 in a position which is rotatedby 180° about the axis as compared with the illustrated position. Thisis made possible by the feature that the recess 16 in the needle unit 3extends approximately symmetrically with respect to the air feed bore 17in the peripheral direction over an angle α (FIG. 3) of 181°-270° sothat this recess 16 will be in communication with the lateral air inletopening 15 of the sleeve 7 in the illustrated position of the needleunit 3 as well as in the position of the latter which is rotated by180°. However, in order to take care that the needle unit 3 is notinadvertently inserted in the sleeve 7 with the position rotated by180°, the bayonet catch can be designed so that the needle unit 3 canonly be inserted in one position. As can be seen from FIG. 4, theprojection 31 of the bayonet catch 33 is, as measured in the peripheraldirection, wider than the projection 32. The projections 29 and 30 ofthe needle unit 3 have a mutual spacing on one side (on the right-handside in FIG. 4) corresponding to the width of the projection 31 and havea smaller spacing on the other side (on the left-hand side in FIG. 4)corresponding to the width of the projection 32. The needle unit 3 thuscan only be inserted in a position wherein the larger spacing betweenprojections 29 and 30 is aligned with respect to the wider projection31, and can then be turned by 90° into the position illustrated herein.This turning step is restricted to 90°, for example by means of stops29.1 and 30.1, respectively, arranged on projections 29 and 30 andcooperating with the projections 31 and 32, respectively. In order to beable to insert the needle unit 3 in the position rotated by 180°, thebayonet ring 33 (after removal of the snap ring 34) must be removed fromthe housing 9 and reinserted after rotating by 180°. The two positionsof the bayonet ring 33, turned by 180° with respect to each other, arefixed, for example, by a cam 33.1 at the bayonet ring 33 received in oneof two mutually diametrically opposed recesses 9.1 and 9.2,respectively, in the housing 9.

FIG. 5 shows another version in a view of a detail of FIG. 1 on anenlarged scale. Also in this version, the needle unit 3' is in directcontact with the guide unit 1; the needle unit 3', however, does notcontact the end face of the guide unit 1 but rather the wall of theconical bore section 2. Projections 3.1, 3.2, 3.3 are arranged,distributed over the periphery, on the conical peripheral surface 5 ofthe needle unit 3'; these projections are in contact with the wall ofthe conical bore section 2. Thus, the width of the passage slot 6between the peripheral surface 5 and the wall of the bore section 2corresponds exactly to the height of the projections 3.1, 3.2, 3.3.

In the blow-texturing device described in FIGS. 1-4, the axle 22 aboutwhich the baffle unit 20 is pivotable with its mandrel 21 and the body23 is arranged transversely to the axis of the guide unit 1 and of theneedle unit 3, i.e. it intersects this axis approximatelyperpendicularly. The baffle unit 20 could, of course, also be pivotableabout a differently arranged axle between the position at apredetermined small spacing in front of the outlet orifice of the boreof the guide unit and a threading position remote from this outletorifice. For example, in the version according to FIGS. 7 and 8, themandrel 21 carrying the sleeve-shaped baffle unit 20 is held in a body23' which carries a pivot axle 22' which is approximately in parallel tothe axis of the guide unit 1. The pivot axle 22' is supported in aholder 24' attached to the sleeve 7. A compression spring 25' isarranged in a bore in the holder 24'; this spring urges a ball 26' intoa detent notch 27' in the swivel axle 22'. Thereby the body 23' with themandrel 21 is fixed in the operating position wherein the body 23' is incontact with a stop 24.1 and the baffle unit 20 is located in front ofthe outlet orifice of the bore of the guide unit 1. For threading a newmultifilament yarn, the body 23' can be swung with the axle 22' into theposition shown in FIG. 8 in broken lines wherein the ball 26' engagesinto a second detent notch 28' in the axle 22'.

I claim:
 1. A device for blow-texturing at least one multifilament yarn,with a guide unit (1) containing a through bore having a conical section(2) on one inlet side, and with a needle unit (3; 3') containing athrough yarn passage (4) aligned approximately coaxially with the boreof the guide unit (1), this needle unit extending with one end into theaforementioned conical section (2) and exhibiting on this end a conicalperipheral surface (5) forming, with the wall of the conical section(2), a passage slot (6) for a blowing medium, wherein the axial positionof the guide unit (1) with respect to the needle unit (3;3') is fixed bypressing the guide unit (1) and the needle unit (3;3') together in theaxial direction by means of an exerted force, a feed bore (17) for theblowing medium terminating into the annular chamber (18) surrounding theneedle unit (3;3') in front of the passage slot (6), and a baffle unit(20) being mounted on the outlet side of the bore of the guide unit (1),wherein the needle unit (3; 3') is displaceably guided in a sleeve (7)and is retained in a housing (9) axailly movable on the sleeve (7) bymeans of a bayonet catch (29, 30, 31, 32); and that the aforementionedexerted force is produced by springs (11, 12) acting between the housing(9) and the sleeve (7) as well as, during operation, by the pressure ofthe blowing medium effective upon the sleeve (7) between the housing (9)and a flange (7.2).
 2. Device according to claim 1, wherein the guideunit (1) and the needle unit (3; 3') are in direct contact with eachother.
 3. Device according to claim 2, wherein the guide unit (1) is incontact with the needle unit (3) along an annular surface (8).
 4. Deviceaccording to claim 2, wherein the guide unit (1) is in contact with theneedle unit (3') on projections (3.1, 3.2, 3.3 ) arranged in the passageslot (6).
 5. Device according to claim 1, wherein the bayonet catch (29,30, 31, 32) exhibits radial projections (29, 30) carried by the needleunit (3; 3') with differing spacings or differing widths, and, in a ring(33) connected with the housing (9), passage recesses with differingwidths and, respectively, differing mutual spacings, in such a way thatthe needle unit (3; 3') can be introduced in only one angular positioninto the sleeve (7) and then is turnable in the sleeve (7) into only onefinal position.
 6. Device according to claim 5, wherein the ring (33) isreleasably connected with the housing (9) and can be fixed in thehousing (9) in two positions rotated with respect to each other by about180°.
 7. Device according to claim 1, wherein the needle unit (3; 3')exhibits a cylindrical section guided in a sleeve (7) and a centralprojection of a smaller diameter emanating from an end face of thissection and carrying the conical peripheral surface (5), the feed bore(17) being approximately in parallel to the axis of the yarn passage (4)and emanating from a recess (16) in the cylindrical section extending inthe peripheral direction, a transverse bore (15) in the sleeve (7)terminating into this recess (16), wherein the recess (16) extends inthe peripheral direction over an angle (α) of 180°-270° so that the feedbore (17) in the needle unit (3; 3') communicates with the transversebore (15) in two positions of the needle unit (3; 3') rotated by about180° with respect to each other.
 8. Device according to claim 1, whereinthe baffle unit (20) is exchangeable and, being pivotable into athreading position removed from the outlet orifice of the bore of theguide unit (1), is retained on a holder (24; 24') fixed at least axiallywith respect to the guide unit (1).
 9. Device according to claim 1characterized in that a bushing (19) with a rounded inlet rim is seatedin the feed bore (17).